Superior Transcoding Capabilities Help Reinvent Business Enterprise Services

WESTFORD, Mass., May 29, 2008 – Sonus Networks, Inc. (Nasdaq: SONS), a market leader in IP communications infrastructure, today announced that Tortel Communications Inc., a leading provider of pure IP-telephony solutions with a strong presence in the United States, Canada, India and Asia, has selected Sonus to replace its incumbent IP-voice network technology.

Tortel is replacing its legacy solution to improve the overall quality of service and integrity of its network. The Company also required a robust, next-generation solution to enable it to develop and deliver differentiating product offerings and an improved long distance offering. Due to the simplified network management and efficient transcoding capabilities of Sonus' gateway solution, Tortel expects a substantial increase in its network performance and the ability to devote additional resources to the development of new services.

"We conducted a thorough review of competitive solutions before selecting Sonus Networks to serve as the cornerstone of our enhanced next-generation long distance voice network," said Dominic Ogbonna, Chief Technology Officer for Tortel Communications. "Sonus was the only vendor able to provide a solution that met our requirements for security, scalability, reliability and management. In addition, by partnering with Sonus, we saw the opportunity to deliver operational savings and build new revenue streams through service creation."

Tortel will utilize Sonus' Network Border Switch (NBS), built on the market-leading GSX9000 platform, which offers carrier class IP-peering and a strong layer of security. Tortel will take advantage of the peering and advanced transcoding capabilities that Sonus allows to be built directly into the gateway, streamlining the switching of traffic between IP-networks and simplifying network management.

"Tortel is emerging as one of Canada's leading suppliers of pure IP-telephony and has shown considerable innovation in developing its networks to enhance customer experience," said Hassan Ahmed, president, chairman and CEO, Sonus Networks. "Whether wireline or wireless, we are supporting forward thinking companies like Tortel in their ambitions to generate new services for their customers and differentiate their offerings with market leading IP-services."

About Sonus Networks

Sonus Networks, Inc. is a leading provider of IP-voice infrastructure solutions for wireline and wireless service providers. With its comprehensive IP Multimedia Subsystem (IMS) solution, Sonus addresses the full range of carrier applications, including residential and business voice services, wireless voice and multimedia, trunking and tandem switching, carrier interconnection and enhanced services. Sonus' voice infrastructure solutions are deployed in service provider networks worldwide. Founded in 1997, Sonus is headquartered in Westford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

This release may contain forward-looking statements regarding future events that involve risks and uncertainties. Readers are cautioned that these forward-looking statements are only predictions and may differ materially from actual future events or results. Readers are referred to Item 1A "Risk Factors" of Sonus' Quarterly Report on Form 10-Q for the period ended March 31, 2008, filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements. Risk factors include among others: the impact of material weaknesses in our disclosure controls and procedures and our internal control over financial reporting on our ability to report our financial results timely and accurately; the unpredictability of our quarterly financial results; risks and uncertainties associated with the Company's restatement of its historical stock option granting practices and accounting including regulatory actions or litigation; risks associated with our international expansion and growth; consolidation in the telecommunications industry; and potential costs resulting from pending securities and patent litigation against the Company. Any forward-looking statements represent Sonus' views only as of today and should not be relied upon as representing Sonus' views as of any subsequent date. While Sonus may elect to update forward-looking statements at some point, Sonus specifically disclaims any obligation to do so, except as required by law.

Sonus is a registered trademark of Sonus Networks, Inc. All other company and product names may be trademarks of the respective companies with which they are associated.